I use the trailmax guardian scabbards. They only get used about 10 days a year, so I don't see the need for a full custom leather job. I like how well they protect the rifles, I use them as travel cases as well....
When I carry a rifle horseback it's always been in the "Northwest" position.
I prefer the rifle to be a little more rearward (by at least a few inches) than these pictures show but I was borrowing a scabbard for my lever action .30-06 and this was as far back as I could get that particular scabbard.